Lateral Cephalometric Radiographs Research Articles

Age and sex estimation using fractal analysis in Brazilian adults: a discriminant analysis

This study assessed the accuracy of fractal analysis (FA) to estimate chronological age and sex in Brazilian adults for forensic investigations. The gender-balanced sample comprised lateral cephalometric radiographs of 120 individuals, stratified according to age (20-29, 30-39, 40-49, 50-59 years) and sex (female and male). A trained calibrated examiner measured the fractal dimension (FD) of the mandibular ramus and mandibular angle. Linear regression and multiple logistic discriminant analysis were carried out to explore the accuracy of FA. For all analyses, p-values < .05 indicated statistical significance. Overall, mean FD values were 1.49±0.10 for the mandibular ramus and 1.48±0.09 for mandibular angle. Results were more accurate in males than females for discriminating age and sex. The multiple discriminant analysis indicated that FA distinguished sex in 61.7% males and 58.3% females. In addition, the mean difference between actual and predicted value was 9.5 years and 10.1 years for men and women, respectively. Fractal analysis accurately identified sex- and age-related differences in the trabecular pattern of the mandible of Brazilian adults, confirming its utility for forensic investigations. Further studies investigating other populations are needed to assess the accuracy of FA for Forensic Dentistry.

Effects of long-term use of the lower lingual arch from 8.5 years to 13.2 years

To investigate the effects of long-term use of the lower lingual arch (LLA) on the sagittal and vertical positions of the permanent lower incisors and first molars. The sample consisted of 98 patients who were treated with an LLA (LLA group) and 39 patients who were treated without an LLA (no-LLA group). The positional changes of the lower incisors and first molars were analyzed after performing mandibular structural superimpositions on lateral cephalometric radiographs taken before treatment (T1) and at the end of LLA therapy (T2). The mean ages at T1 and T2 were 8.5 years and 13.2 years, respectively. Study casts were analyzed to quantify arch dimensional changes. Mesial movement of the lower molar cusp was similar between the LLA and no-LLA groups, but the vertical position was slightly greater at T2 in the LLA group. In the LLA group, there was a molar tip-back effect, and the lower incisors were proclined 4.2° more than in the no-LLA group. Arch perimeter decreased 3.6 ± 2.6 mm without an LLA and 0.97 ± 3.7 mm with an LLA. Intercanine and intermolar widths both increased about 1 mm more with an LLA (P < .0001). The LLA does not seem to restrict mesial movement and vertical eruption of the lower incisors and molars in the long term. The LLA effectively preserves the arch perimeter at the expense of a slight lower incisor proclination.

Lower Incisor Positions in Different Malocclusions and Facial Pattern

Aims: The position of lower incisor has been of significant concern when seeking orthodontic treatment plan, it has been recognized as one of diagnostic key and play an important in the development of normal occlusion and facial pattern. This study was aimed at the determination of lower incisor position and its possible association with different sagittal malocclusions and facial patterns.&#x0D; Study Design: Descriptive Cross-sectional Study&#x0D; Place and Duration of Study: Department of Orthodontics Institute of Dentistry Liaquat University Medical and Health Sciences (LUMHS) Jamshoro between June 2019 to July 2020.&#x0D; Methodology: Ninety-seven pre-treatment lateral cephalometric radiographies were taken, and they were classified sagittally into skeletal class I, II and III, and vertically into normodivergent, hyperdivergent and hypodivergent facial pattern using ANB and SNMP, respectively. Lower incisor position was assessed by means of FMIA and IMPA. One way analysis of variance (ANOVA) was applied to check any association between lower incisor position and sagittal malocclusion and facial pattern. P value of 0.05 was considered statistically significant.&#x0D; Results: The study sample consisted of 97 patients. The mean age of the patients was 25.55 SD ±3.93. The mean SNMP value was 28.84 SD ±7.354 and mean ANB value 4.809 SD ±3.85. Mean Incisor position based on IMPA was 98.598 SD ± 9.413 and FMIA 54 SD ±9.995. Intra and interobserver reliability was assessed with intraclass correlation coefficient values ranging between 0.825 and 0.990 respectively. The ANOVA test results showed significant relationship between the sagittal malocclusion and incisor position with P value .036. The Bonferroni analysis indicated that statistically significant association existed in term of lower incisor position between Class II and Class III malocclusion with P value .047. Test results further indicated that there is no significant difference in the position of lower incisor in relation to facial pattern with P value .355.&#x0D; Conclusions: Statistically significant association was found between lower incisor position with respect to the sagittal malocclusion. However, no significant association was found between facial pattern and lower incisor position.

Comparison of maxillary sinus on radiograph among males and females

Background: An obstacle in forensic odontology is an incomplete body caused by post-mortem damage. The problem can be solved by using lateral cephalometric radiographs for victim identification. Sex determination can be performed on the maxillary sinus, which is the largest among the paranasal sinuses. Purpose: This study aims to analyse the maxillary sinuses’ width and height on lateral cephalometric radiographs among male and female subjects. Methods: The study samples were 60 lateral cephalometric radiographs (30 males and 30 females) between the ages of 20 and 40, with complete permanent dentition (or third molar absence). The height and the width of maxillary sinus measurement were performed using measurement tools of EzDent-i Vatech Software. Results: The average width of the maxillary sinus on males was 40.60 ± 1.56 mm, and the height was 35.02 ± 2.09 mm, while the width and the height on females were 36.93 ± 1.30 mm and 29.72 ± 1.76 mm, respectively. The independent t-test reveals a significant difference (p&lt;0.05) between males and females, both in the maxillary sinus’s width and height on the lateral cephalometric radiograph. Conclusion: The maxillary sinus in males is larger than in females, it opening up possibilities for disaster victim identification.

Occipital spurs on lateral cephalometric radiographs: morphologic and morphometric features.

To evaluate the presence of occipital spurs, morphologic/morphometric features, and the presence of ossification of ligamentum nuchae (ONL) on lateral cephalometric radiographs of individuals aged under and over 18years. Lateral cephalometric radiographs of 1430 individuals aged between 14-50years were scanned. The presence of ONL and occipital spurs was evaluated in 1312 patients who met the inclusion criteria, and existing occipital spurs were measured and their types (flat/crest/spine) were recorded. Occipital spurs were detected in 63 patients aged over 18years (63/120; 52.5%) and 57 patients aged under 18years (57/120; 47.5%). When the spur length by age category and sex was evaluated, no statistically significant difference was observed. The spur types seen were flat (40.8%; 49/120), crest (30%; 36/120) and spine (29.2%; 35/120), respectively. Although there was no statistically significant difference between the spur types seen in terms of age, a significant difference was observed between the sexes in the total group (p < 0.001). Spine-type spurs (66.7%; 18/27) were the most common in females, and flat-type spurs (45.2%; 42/39) were the most common in males. ONL was detected in only three individuals. No relationship was found between the presence of occipital spurs and ONL. Although spur length was not affected by age and sex, spur types were found to vary according to sex. Occipital spurs are mostly asymptomatic and detected incidentally on lateral cephalometric radiographs. They are one of the important anatomic formations that should be diagnosed by physicians.

Influence of Orthodontist’s Gender and Experience on the Perception of Dentoskeletal Parameters Using Cephalometric Radiographs: A Questionnaire Study

AIM: The aim of the study was to evaluate the influence of orthodontist’s gender and experience on the perception of dentoskeletal parameters through cephalometric radiographs. METHODS:An online survey was developed using six laterals cephalometric radiographs. The survey included questions about clinicians’ demographics as well as questions about the selected radiographs. The survey was distributed through Egyptian association of orthodontist’s partner to 200 members. RESULTS: comparison between orthodontists with three level of experience showed there was a statistically significant difference between the three groups regarding total score of correct tracing [P-value = 0.004, Effect size = 0.085]. Pair-wise comparisons revealed that Orthodontists with more than 10 years of experience showed the statistically significantly highest median score. There was no statistically significant difference between Orthodontists with experience less than 5 years and those with 5 – 10 years of experience; both showed statistically significantly lower median scores. CONCLUSIONS: Orthodontist with more than 10 year of experience showed higher prevalence of perception of dento- skeletal parameters on lateral cephalometric radiographs than the less experienced groups. No association was found between clinicians’ gender and perception of dento-skeletal parameters

Accuracy of 3 Soft Tissue Prediction Methods After Double-Jaw Orthognathic Surgery in Class III Patients.

We aimed to evaluate the accuracy and validity of conventional manual prediction method (CM) and 2-dimensional and 3-dimensional (3D) soft tissue prediction methods for Class III bimaxillary orthognathic surgery patients. Twenty skeletal Class III patients were included in this study. Soft tissue prediction was achieved with a traditional manual technique, 2-dimensional software (Dolphin Imaging, version 11.5), and 3-dimensional software (SimPlant Master, version 16.0) on preoperative lateral cephalometric radiographs and cone beam computurized tomography (CBCT) images and then compared with postoperative lateral cephalometric radiographs obtained at least 6 months after surgery (mean, 11.5 ± 6.77 months). Forty-eight measurements were done to determine the reliability of the methods. All prediction methods have limited postsurgery prediction accuracy for the subnasal upper lip area. Most of the differences were not more than 3 mm for all study groups, except the 3D software, which predicted the upper lip area to be, on average, 3.08 ± 1.38 mm further back (P < 0.001). Although the conventional method predicted 20 of 48 measurements similar to the final results, the poorest predictions were found at the nasal and labiomental areas (P < 0.001). Two-dimensional software predicted 23 of 48 measurements very close to the final results but made significantly different predictions for the nasolabial and labiomental angles, labrale superius point, and the chin area. The 3D method predicted, especially the upper lip area, to be significantly and clinically incorrect, and its soft tissue prediction was insufficient compared with the other 2 methods. The 3D software needs to be updated, especially in evaluating soft tissue A point and upper lip changes after surgery.

Characteristics of Skeletal Archial Analysis Facial Patterns in Adult Obstructive Sleep Apnea

IntroductionSkeletal archial analysis in adult OSA has not been characterized. The specific aim of this study was to characterize archial analyses of adult subjects with known OSA. The primary research question of this study was: “What is the frequency of skeletal patterns from archial analysis in adult OSA subjects?” The authors hypothesized that adult subjects with OSA will follow a retrusive pattern skeletal archial analysis with high correlation with OSA severity. Materials and methodsA retrospective cohort study of adult polysomnogram (PSG)-confirmed OSA subjects’ charts was designed from subjects who presented to Allegheny General Hospital Division of Oral and Maxillofacial Surgery between January 1, 1992, and December 31, 2017. Inclusion criteria included PSG-confirmed OSA (AHI > 5), diagnostic lateral cephalometric radiographs, and demographic and diagnostic data. Exclusion criteria included subjects with a history of maxillofacial trauma or tumor surgery, craniofacial syndromes, and inadequate chart records. Independent predictor variables were age, sex, body-mass index (BMI), anterior arc independent (continuous data), and combined horizontal and vertical analyses (categorical data). Lateral cephalometric radiographs were analyzed with Dolphin software (v. 11.8) for Sassouni Plus archial analysis. Anterior arc analysis was recorded for maxillary incisor position to ANS (U1 - ANS arc), Point B to Point A arc (B - A arc), and pogonion to ANS arc (Pg - ANS arc). Skeletal facial types were categorized into 27 distinct facial types. Statistical analysisStandard descriptive and Spearman correlation (□) analysis was used with Excel. Results were reported as mean, standard deviation, and percentages. Standard error of measurement (SEM) and post-hoc power analysis were completed. Statistical significance was set at the P < .05 level. ResultsA total of 171 subject charts that met the inclusion criteria were included in this study. The cohort consisted of 124 females (73%). The cohort mean for age was 47 years (Standard deviation [SD] 11), for BMI 31 (6.5), for AHI 42 (30.5), for ESS 13 (4.9), and for nO2 81% (11). All ICC were greater than or equal to 0.90. Skeletal archial analyses revealed that the most frequent skeletal patterns were Class III at 44.7% (77/171), bimaxillary retrusion at 27% (46/171), Class II at 21.1% (36/171), Class I at 6.6% (11/152), and bimaxillary prognathism at 0.6% (1/171). Relative to the anterior arc, maxillary position was retrusive in 82.2% (141/171), ideal in 11.2% (19/171), and protrusive in 6.6% (11/171) of subjects. Also, relative the anterior arc, the mandible was in an ideal position in 45.3% (78/171), retrognathic in 33.6% (57/171), and prognathic in 21.1% (36/171) of subjects. Long vertical skeletal pattern was most frequent at 81.6% (140/171), normal at 14.5% (25/171), and short at 3.9% (7/171) of subjects. The most frequent skeletal patterns were Maxilla Retro, Mand Ideal AP; Long Vertical (49/171, 28.9%), Bi-Skeletal Retro AP; Short Vertical (41/171, 23.7%), and Maxilla Retro, Mand Prog AP; Long Vertical (26/171, 15.1%). There were only weak correlations between all independent and dependent variables (range P = .05 to .19). ConclusionWithin the limitations of this study, maxillary and bimaxillary retrusion patterns were frequent horizontal archial analysis skeletal positions as was long lower facial height. Most skeletal patterns involved maxillary retrusion, generally with long vertical lower face. All of the horizontal archial skeletal positions had weak correlations with severity of adult OSA. Additional research may be required to fully analyze the full diagnostic potential of skeletal archial analysis in diagnosis and treatment planning of subjects with OSAS.

Archial Skeletal Analysis is not a Significant Predictor of Adult OSA Syndrome Severity

IntroductionArchial analyses may be a useful tool in the diagnosis and treatment planning of adult OSA. The purpose of this study was to evaluate the association of vertical and horizontal archial analyses on predictors of the severity of OSA. The primary research question of this study was: “Does facial skeletal archial analysis predict severity of OSA?” The authors hypothesize that archial analyses will predict severity of adult OSA. Subjects and methodsA retrospective cohort study of adult polysomnogram (PSG)-confirmed OSA subjects’ charts was designed from subjects who presented to Allegheny General Hospital Division of Oral and Maxillofacial Surgery between January 1, 1992, and December 31, 2017. Inclusion criteria included PSG-confirmed OSA (AHI > 5), diagnostic lateral cephalometric radiographs, and demographic data. Exclusion criteria included subjects with a history of maxillofacial trauma or tumor surgery, craniofacial syndromes, and inadequate chart records. Independent predictor variables were age, sex, body-mass index (BMI), anterior arc independent (continuous data), and combined horizontal and vertical analyses (categorical data). Skeletal facial types were categorized into 27 distinct facial types based on combined anterior horizontal and vertical arcs. Primary outcome variable was severity of OSA as defined by apnea-hypopnea index (AHI). Secondary outcome variables included Epworth sleepiness scale (ESS) and lowest oxygen saturation (nO2). Lateral cephalometric radiographs were analyzed with Dolphin software (v. 11.8) for Sassouni Plus archial analysis. Anterior arc analysis was recorded for maxillary incisor position to ANS (U1 - ANS arc), Point B to Point A arc (B - A arc), and pogonion to ANS arc (Pg - ANS arc). Statistical analysisStandard descriptive analysis, multiple linear regression on continuous variables, and multinomial logistic regression on categorical and dummy variables were performed using XLSTAT. Stratified by sex, multilinear regression was performed on anterior arc analyses. Continuous variables (median values) and categorical data were transformed to dummy variables for multinomial logistic regression. Results were reported as mean, standard deviation, and odds ratio (OR). Standard error of measurement (SEM) was completed on repeated cephalometric analyses of 20 randomly selected radiographs. Statistical significance was set at P < .05 level. ResultsA total of 171 subject charts that met the inclusion criteria were included in this study. The cohort consisted of 124 females (72.5%). The cohort mean for age was 47 years (Standard deviation [SD] 11), for BMI 31 (6.5), for AHI 42 (30.5), for ESS 13 (4.9), and for nO2 81% (11). All SEM were greater than or equal to 0.90. Stratified by sex, and controlling for age and BMI, no statistically significant associations for anterior archial analyses (U1 - ANS arc, B - A arc, or Pg - ANS arc) and severity of adult OSAS were found. Multinomial logistic regression revealed that none of the archial skeletal classifications were significant predictors of the severity of OSAS (AHI OR = 1.0, P = .89; ESS OR = 0.99, P = .70; nO2 OR = 1.0, P = .81). ConclusionWithin the limitations of this study, when controlling for age, sex, and BMI, anterior horizontal archial analyses were not significantly associated with, and archial skeletal facial types were not significant predictors for, OSAS severity as defined by AHI, ESS, or nO2. Additional research may be required to fully analyze the full diagnostic potential of skeletal archial analysis in diagnosis and treatment planning of subjects with OSAS.

The Stability of Anterior Open Bite Closure After Bimaxillary Osteotomy.

The aim of this study was to evaluate the long-term success rate of combined surgical-orthodontic therapy of skeletal anterior open bite. A total of 11 patients with an anterior open bite treated with a combined surgical-orthodontic therapy were retrospectively analysed via lateral cephalometric radiographs and models before treatment, 7-10 days after surgery (T1), one year post-operatively (T2) and two years post-operatively (T3). Ten patients continued to experience a positive overbite at T2. This decreased to 8 at T3. Three patients experienced relapse and had a negative overbite at T3. The average pre-treatment overbite was greater in the positive overbite group compared to the relapse group. Spearman's correlation analysis revealed a correlation between preoperative maxilla-mandibular plane angle (MMPA) with the overall change in overbite. Friedman's test followed by Bonferroni post-hoc analysis was carried out to identify any statistical significance. In conclusion, combined surgical-orthodontic treatment achieves good results for anterior open bite. Patients with a high pre-operative MMPA have a higher risk of relapse. Lower anterior facial height ratio to total anterior facial height (LAFH/TAFH) and the amount of impaction do not significantly contribute to the risk of relapse. Long-term stability of overbite for anterior open bite patients should be around 75%.

Association between Polymorphisms in the IL-1β, TNFRSF11B, CASP1, and IL-6 Genes and Orthodontic-Induced External Apical Root Resorption.

Orthodontic-induced external apical root resorption (EARR) is a severe condition affecting the roots of the teeth, whose genetic causes have been inconclusive to date. The aim of the present study was to assess the influence of selected single nucleotide polymorphisms (SNPs) IL-1β, TNFRSF11B, CASP1, and IL-6 genes on post-orthodontic EARR. A sample of 101 patients with clearly assessable orthopantomograms and lateral cephalometric radiographs taken before and at the end of the orthodontic treatment was used to evaluate the presence of EARR. The association between genetic polymorphisms and EARR was assessed with the Chi2 test. A binary logistic multi-level model was built to evaluate the ability of patient- and tooth-level variables to predict EARR occurrence. The overall prevalence of EARR resulted to be around 40%. Within the limitations of this study, a significant association was found between EARR presence and the SNP for the IL-1β gene but not for the TNFRSF11B, CASP1, and the IL-6 genes. The final multi-level model demonstrated that the SNP for the IL-1β gene increases the odds of developing EARR by around four times. Since there is currently no accurate method to determine which patients will develop EARR prior to orthodontic treatment, further studies are needed to investigate the predictive ability of further genetic variants on EARR development.

Ultra short time to Echo (UTE) MRI for cephalometric analysis-Potential of an x-ray free fast cephalometric projection technique.

ObjectivesA novel magnetic resonance imaging (MRI) scan protocol is presented on the basis of ultra-short time to echo (UTE). By this MRI cephalometric projections (MCPs) can be acquired without the need of post processing in one shot. Different technical parameterizations of the protocol are performed. Their impact on the performance of MCPs is evaluated in comparison to the gold standard–the lateral cephalometric radiography (LCR) for cephalometric analysis (CA) in orthodontics.MethodsSeven MCPs with various scan parameters influencing the scan duration and one LCR are used from one subject. 40 expert assessors performed CA for 14 predefined cephalometric landmarks. Relative metric distances and absolute angular measurements were calculated. Statistical analysis is presented and the deviations are highlighted to demonstrate the potential of the method for further analysis.ResultsThe MCPs are acquired in 5–154 seconds, depending on resolution and contrast. Mean relative distances were 2.4–2.7 mm in MCPs and 1.6 mm in LCR, which demonstrate the accuracy and level of agreement of the expert assessors in identifying anatomical landmarks. In comparison to other studies, the presented MCP performed similar in angular analysis and demonstrated on average deviation of 1.2° ±1.1° in comparison to LCR. Despite the point articulare (Ar) and the related gonial angle the calculate distances and angles show outcomes in the range of ±2°/2mm.ConclusionsMCPs can be acquired much faster in comparison to other techniques known from literature for CA. This study demonstrated the potential of the new method and showed first feasible results. Further research is needed to analyze the performance on a broad range of patients.

Prevalence and characteristics of mandibular divergency in class III patients

Introduction: The classical skeletal divisions of orthodontic patients are the Angle's classification of Classes I, II, and III and of mandibular inclination into normo-, hypo-, or hyperdivergent. Of these classifications, Class III and hyperdivergent are the least studied. This study aimed to investigate the prevalence and relationship between Class III and hyperdivergency. Materials and Methods: Lateral cephalometric radiographs of Class III patients were collected from Riyadh Elm University and were traced by WebCephTM software and measured for 16 linear and angular measurements to determine anteroposterior, vertical, and dental associations. To determine the anteroposterior relationships, Sella-Nasion to A point Angle, Sella-Nasion to B point Angle, A point to B point Angle, and Wits appraisal were used. Class III status was determined by utilizing (A point to B point Angle &lt;1) and (Wits appraisal &lt;−2.5). The vertical divergency pattern was considered according to normal Frankfort horizontal plane and mandibular plane (FMA) (22°–28°) and SN-GoMe: Sella-Nasion to Mandibular plane (27°–36°) measurements. The dental correlation was considered according to upper incisor to maxillary plane (U1-Mx) and lower incisor to mandibular plane angle. Statistical analysis was performed with SPSS (version 25) software. Results and Conclusions: One hundred and twenty-five Class III patients were included in the final analysis of this study. A significant correlation at 0.650 was discovered between ANB and Wits analyses (&lt;0.001). Subjects data was grouped, based on their mandibular divergency, into hypodivergent, normodivergent, and hyperdivergent. The distribution, regardless of measurement used, was significantly higher in the prevalence of hyperdivergents (FMA 46.4% and SNGoMe 56%) over hypo- and normodivergents. Although FMA and SNGoMe were positively correlated at 0.887, there were significant differences in their classification of divergency with higher levels of hyperdivergency with SNGoMe.

Transverse dentofacial dimensions according to skeletal maturation

Aim: This study aimed to determine the dentofacial transverse dimensions according to the hand-wrist and cervical vertebrae skeletal maturation stages in order to evaluate the differences between the sexes, to identify the correlations between transverse measurements, and to compare the transverse measurements of individuals of different origins with those of Turkish individuals.&#x0D; Methodology: Transverse measurements were performed using the posteroanterior radiographs of 265 Turkish individuals (150 females, 115 males) at 7–17 years of age. Skeletal maturation was evaluated using hand-wrist radiographs and lateral cephalometric radiographs, and the results were used to categorize the patients into 3 stages of hand-wrist skeletal maturity (prepubertal/pubertal/postpubertal) and 2 stages of cervical vertebrae maturity (prespurt/postspurt). Seven measurements were evaluated. A multivariate linear regression model was used to evaluate the correlations between transverse measurements and the variables of skeletal age and sex.&#x0D; Results: Sex was a significant explanatory factor for all transverse variables. In the postpubertal and postspurt stages, all transverse measurement values were found to be higher in males. Postpubertal term was a significant explanatory factor for maxillary, mandibular, mandibular intermolar, and maxillary intermolar widths, whereas pubertal term was only a significant explanatory factor for maxillary intermolar width.&#x0D; Conclusion: Skeletal age and sex should be taken into account when determining transverse dentofacial measurements.&#x0D; &#x0D; How to cite this article: Sezen Erhamza T, Akan B, Nazik Ünver F, Evli Dalgalı P. Transverse dentofacial dimensions according. Int Dent Res 2021;11(2):99-108. https://doi.org/10.5577/intdentres.2021.vol11.no2.7&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Sagittal split ramus osteotomy, intraoral vertical ramus osteotomy, and lateral corticectomy for asymmetric mandibular prognathism.

ObjectivesThe purpose of this study was to evaluate the postoperative anteroposterior stability and improvements in facial asymmetry after performing LeFort I osteotomy in the maxilla, sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) in the mandible, and lateral corticectomy on the IVRO side.Materials and MethodsFrom July 2009 to October 2018, a retrospective analysis was performed on 11 subjects. Lateral cephalometric radiograph was performed preoperatively (T0), postoperatively (T1), and at 12 months of follow-up (T2), and the B point distance was measured. Posteroanterior cephalometric radiograph was performed preoperatively (S0) and at 12 months of follow-up (S1) and was used to measure five indicators (Ag angle, M-Ag, Co-Ag, Co-Me, and Ag-Me) of facial asymmetry.ResultsThe B point distances for T0 and T1 were significantly different (P=0.007), whereas those for T1 and T2 were not significantly different (P=0.1). In addition, there was a significant difference between the B point distances of T2 and T0 (P=0.026). Comparison of the facial asymmetry indicators before and after surgery showed a significant difference for all indicators between S0 and S1 the P-values of Ag angle, M-Ag, Co-Ag, Co-Me, and Ag-Me were 0.003, 0.003, 0.008, 0.006, and 0.004, respectively. The Z value was based on negative ranks.ConclusionThere was no significant difference in the B point distances from postoperation to the 12-month follow-up. However, there were significant differences in all five indicators related to facial asymmetry before and after surgery. The values for the five indicators of facial asymmetry all increased postoperatively.

Biotypic classification of facial profiles using discrete cosine transforms on lateral radiographs

ObjectiveThe aim of the study was to use discrete cosine transforms to graph soft tissue curves in lateral cephalometric radiographs and, with the obtained mathematical values, to group these curves by both traditional biotypes and cluster systems, in order to evaluate discriminatory capacity in terms of accuracy. DesignA sample of 625 lateral radiographs of adult patients (319 women and 306 men) was classified by facial biotype based on the ANB angle and mandibular plane angle. The curves of the facial profile were digitized with 50 equidistant points and discrete cosine transform was applied to analyze these curves mathematically for the determination of the accuracy of the classification of traditional biotypes. Phylogram cluster analysis was then performed for hierarchical grouping and accuracy was determined through cross-validation. ResultsGrouping by biotype was performed for men and women separately. Although significant, accuracy did not surpass 71.4%. In the groups by clusters, significant results were achieved when performing four analyses for men and two for women. The best accuracy regarding classification power and qualitative distinction was 89.5% for men and 94% for women. ConclusionsDiscrete cosine transforms using a cluster system had greater discriminatory capacity in terms of accuracy compared to traditional grouping considering the ANB angle and mandibular plane angle. This exploration can be useful for the creation of a soft-tissue facial reconstruction software for the Latin American population.

Comparison of Deep Learning Models for Cervical Vertebral Maturation Stage Classification on Lateral Cephalometric Radiographs.

The purpose of this study is to evaluate and compare the performance of six state-of-the-art convolutional neural network (CNN)-based deep learning models for cervical vertebral maturation (CVM) on lateral cephalometric radiographs, and implement visualization of CVM classification for each model using gradient-weighted class activation map (Grad-CAM) technology. A total of 600 lateral cephalometric radiographs obtained from patients aged 6–19 years between 2013 and 2020 in Pusan National University Dental Hospital were used in this study. ResNet-18, MobileNet-v2, ResNet-50, ResNet-101, Inception-v3, and Inception-ResNet-v2 were tested to determine the optimal pre-trained network architecture. Multi-class classification metrics, accuracy, recall, precision, F1-score, and area under the curve (AUC) values from the receiver operating characteristic (ROC) curve were used to evaluate the performance of the models. All deep learning models demonstrated more than 90% accuracy, with Inception-ResNet-v2 performing the best, relatively. In addition, visualizing each deep learning model using Grad-CAM led to a primary focus on the cervical vertebrae and surrounding structures. The use of these deep learning models in clinical practice will facilitate dental practitioners in making accurate diagnoses and treatment plans.

Le Fort I Osteotomy in Cleft Patients: Maxillary Advancement and Articulation.

Maxillary advancement may affect speech in cleft patients. To examine whether the amount of maxillary advancement and preoperativecephalometric skeletal and dentoalveolar relationships are associated with articulation errors of the Finnish alveolar consonants /s/, /l/, and /r/ in cleft patients. Fifty-seven nonsyndromic cleft patients who underwent Le Fort I or bimaxillary osteotomies were evaluated retrospectively. Pre- and post-operative lateral cephalometric radiographs and standardized speech video recordings were analyzed. The Aspin-Welch unequal variance t test, Student t test sign test, intraclass correlation and Kappa statistics were used in the statistical analyses. The mean advancement of the maxilla (point A) was 4.65 mm horizontally (range -2.80 to 11.30) and -3.82 mm vertically (range -14.20 to 3.90). The overall articulation (especially the sounds /s/ and /l/) improved significantly postoperatively, but the amount of maxillary advancement did not affect the articulation. The preoperative mean percentages of /s/, /l/, and /r/ errors were 32%, 33%, 46% and the postoperative percentages 23%, 19%, 40%, respectively. Preoperative articulation errors of /s/ were related to palatal inclination of the upper incisors. Orthognathic surgery may improve articulation errors. The amount of maxillary advancement is not related to the improvement.

DESCRIPTIVE STUDY OF THE CERVICAL SPINE NONSEGMENTATION USING CONE BEAM COMPUTED TOMOGRAPHY

<h3>BACKGROUND</h3> Vertebral nonsegmentation occurs because of segmentation failure of the vertebrae. The etiology of this failure can be congenital or acquired. The congenital nonsegmentation vertebrae may be partial or complete fusion at the body or the articular facets or in the transverse processes. The cervical vertebrae are the most commonly involved in the spine. These vertebrae are routinely visualized in cone beam computed tomography (CBCT), and the diagnosis is more precise in identifying nonsegmentation compared with the higher percentage of the false-positive findings on lateral cephalometric radiographs. <h3>OBJECTIVE(S)</h3> To describe the cervical spine nonsegmentation and any other incidental findings associated with it using CBCT. <h3>STUDY DESIGN</h3> Fifty CBCT radiographic reports were retrieved from the archived cases database of the Oral and Maxillofacial Radiology Department at The University of Iowa, after institutional review board approval. All reports documented nonsegmentation in the cervical spine. Patient age and sex were collected and the scans were assessed for the level of segmentation, the affected side, and any other associated pathosis in the vertebral region. <h3>RESULTS</h3> For the 50 CBCT scans patient age ranged from 11 to 93 years old (average = 52.7). There were 23 male and 27 female patients. The highest number of vertebral nonsegmentation was found between C2 and C3 in 35 patients, followed by 7 cases between C4 and C3. Two cases had fusion between the occipital bone and C1. Two patients had vertebral nonsegmentation in 2 different regions, 1 in C0-C1 and C2-C3 and the other in C2-C3 and C2-C3-C4. Most of the cases had partial nonsegmentation. <h3>DISCUSSION/CONCLUSIONS</h3> Congenital cervical spine nonsegmentation can be easily identified in CBCT scans. These congenital anomalies might be asymptomatic and can cause restricted movement that may lead to neurologic implications. Therefore, the identification and documentation of this abnormality on CBCT scans is highly recommended.

Comparison of Airway Measurements in Rheumatoid Arthritis and Non-rheumatoid Patients using Lateral Cephalometric Radiographs.

The aim of this study was to investigate the potential relationship between the volumetric area of the upper airway and rheumatoid arthritis (RA) by comparing upper airway measurements between patients with and without RA. This case-control study compared upper airway measurements between patients with and without RA using lateral cephalometric radiographs. Two distinct measurements were made: the area of the upper airway, which is defined as "the area extending from the point of the retro-palatal region to the base of the epiglottis," and the distance of the upper airway, which is defined as "the distance between the anterior border of the third cervical vertebra (C3) and the anterior border of the soft tissue of the neck". A single examiner performed all measurements, and the intra-examiner reliability was assessed. Sixty-one RA patients and 95 non-RA patients were included in the case and control groups, respectively. RA patients were significantly older in age and with higher BMI values. Patients with or without RA had Angle Class II as the most prevalent orthodontic classification. The upper airway was slightly narrower in RA patients, resulting in a smaller area, and the length of the upper airway was significantly longer in RA patients. Patients with RA have narrower upper airways as measured on lateral cephalometric radiographs. This may partially explain the high prevalence of obstructive sleep apnea among patients with RA. Focusing on airways measurements when cephalometric radiographs are taken for patients with RA could give some idea about which patient is likely to have OSA.